Solved: How to use an Anthropic Claude API key without browser login

1 min read
claude-codeanthropic-apiapi-keysteaching

Was teaching agentic AI today. Hit a stupid roadblock during the hands-on part.

The plan: Generate a temp Claude API key with strict limits, share it with students, revoke after class. No need for everyone to have paid accounts. Simple.

What actually happened: The Anthropic client library completely broke the workflow. Every time someone used the key, it forced open a browser demanding organizational login. Can’t give 20 students access to my org settings - that’s insane.

Searched everywhere for a way to disable this. Nothing in the docs.

Then a student finds this Reddit thread with the exact fix. Turns out it’s a common problem - CI/CD pipelines, automated scripts, team sharing - everyone hits this wall. The solution? One undocumented parameter in the client.

Writing this down because:

  1. I’ll forget otherwise
  2. You’ll probably hit the same issue
  3. The official docs won’t help you

The fix exists. It’s just hidden like some secret handshake.

The fix

Here is the fix (for macOS and Linux):

Add/edit ~/.claude/settings.json to have:

{
  "apiKeyHelper": "~/.claude/anthropic_key.sh"
}

Add your key to ~/.claude/anthropic_key.sh:

echo "sk-........."
chmod +x ~/.claude/anthropic_key.sh